1. Field of the Invention
The present invention relates generally to beverage dispensers having cold plates for providing cooling of the beverage constituents, and to such beverage dispensers having cold plates with improved heat exchange ability.
2. Background
Beverage dispensers including cold plates having serpentine tubes extending there through for providing cooling of beverage constituents, are well known in the art. Such dispensers include a cold plate forming the bottom of an ice retaining bin for providing heat exchange cooling of the beverage constituents as they flow through the internal tubes. After passing through the cold plate, the tubes are connected to a beverage dispensing array, such as a beverage tower having a plurality of post mix beverage dispensing valves secured thereto. Such dispensers are typically of the "drop-in" type, wherein the cold plate and ice retaining bin are retained below the level of a counter top surface. The tower extends above and along a back edge of the bin, and a door is provided for access to the ice in front of the tower. Cups can then be filled with ice and subsequently filled with beverage by an operator standing behind the counter opposite from the tower.
A problem with such prior art dispensers concerns the problem of "ice bridge" formation. As is known, heat exchange melting of the ice at the top surface of the cold plate can result in the formation of air pockets between the remaining ice and the top surface of the cold plate. When this occurs, the insulating effect of the air pocket greatly reduces heat exchange between the ice and the beverage constituents flowing through the cold plate.
Heretofore, the operator has had to periodically attempt to break these ice bridges and eliminate the air insulation layer. Unfortunately, these ice bridges can occur at the back of the bin in the area thereof underneath the tower where it is difficult, particularly when the bin is substantially full of ice, for the operator to reach and eliminate the problem. Accordingly, it would be very desirable to have a cold plate cooled dispenser wherein any ice bridging only occurs in an area easily accessed by the operator.
With respect to cold plates specifically, it is always desirable to obtain the maximum amount of heat transfer between the ice and the beverage constituents. A problem with present cold plates concerns the fact that a majority of the heat exchange occurs along the first several feet of the serpentine tubes found therein, and very little occurs in the last few feet of each tube. Thus, it would be desirable to increase heat transfer throughout the end few feet of the heat exchange tubes.